1. Technical Field
The present disclosure relates to optical disc devices, particular to a tracking servo and method for tracking an optical disc.
2. Description of Related Art
An optical disc device is capable of reading or writing data from or to an optical disc, such as a CD, a DVD or an HD DVD. The optical disc has many tracks for storing data. The optical disc device includes a spindle motor, an optical head, a focus servo, and a tracking servo. When the optical disc device reads the data from the optical disc, the optical disc device performs the following operations: driving a spindle motor to rotate the optical disc; moving the optical head to inner tracks of the optical disc; driving a focus servo, so the laser light emitted by the optical head is projected on the optical disc; driving a tracking servo to move lens of the optical head so the laser light spot tracks one single data track; reading a track number of the current track to obtain the position of the current track; performing a long tracking for moving the optical head towards the target track from the current track; performing tracking and reading the track number of the track in which the optical head is currently located to obtain the difference between the track number of the current track and that of the target track; performing a short tracking for moving the laser light spot to the target track; and performing tracking and accessing data. However, the conventional optical disc device always performs the long tracking several times, which takes up a large amount of time during tracking.
Therefore, there is room for improvement within the art.